From 09b4ea47d1041612b101c369969db123ac2c1511 Mon Sep 17 00:00:00 2001 From: Ilija Hadzic Date: Fri, 28 Oct 2011 17:43:28 -0400 Subject: drm: make DRM_UNLOCKED ioctls with their own mutex drm_getclient, drm_getstats and drm_getmap (with a few minor adjustments) do not need global mutex, so fix that and make the said ioctls DRM_UNLOCKED. Details: drm_getclient: the only thing that should be protected here is dev->filelist and that is already protected everywhere with dev->struct_mutex. drm_getstats: there is no need for any mutex here because the loop runs through quasi-static (set at load time only) data, and the actual count access is done with atomic_read() drm_getmap already uses dev->struct_mutex to protect dev->maplist, which also used to protect the same structure everywhere else except at three places: * drm_getsarea, which doesn't grab *any* mutex before touching dev->maplist (so no drm_global_mutex doesn't help here either; different issue for a different patch). However, drivers seem to call it only at initialization time so it probably doesn't matter * drm_master_destroy, which is called from drm_master_put, which in turn is protected with dev->struct_mutex everywhere else in drm module, so we are good here too. * drm_getsareactx, which releases the dev->struct_mutex too early, but this patch includes the fix for that. v2: * incorporate comments received from Daniel Vetter * include the (long) explanation above to make it clear what we are doing (and why), also at Daniel Vetter's request * tighten up mutex grab/release locations to only encompass real critical sections, rather than some random code around them Signed-off-by: Ilija Hadzic Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_drv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/drm_drv.c') diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 1919ef05d6d8..ebf7d3f68fc4 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -65,9 +65,9 @@ static struct drm_ioctl_desc drm_ioctls[] = { DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0), DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0), DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY), - DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, 0), - DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0), - DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0), + DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, DRM_UNLOCKED), + DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED), + DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED), DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED), DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER), -- cgit v1.2.1